of chicago



Reissued May 27,1924. I y Re. 15,844 UNITED STATES PATENT OFFICE.

nAnoLn s. asnmv nossr, or cmoaeo, ILLINOIS, assumes an HERBERT A. 2mm,

1 or cnrcaeo, rumors.

INSULATING sonsranoa. R S E D No Drawing: Original mi. 1,402,133, dated January 3, 1922, Serial Nb. 352,903, meet m 20, 1920. Application for reissue filed December 28, 1923. Serial No. 683,257: 1

To all whom it may concern. long fiber asbestos, or in the event the ma- 55 Be it known that I, HAROLD S. ASHEN- terlal is to be used where high heat is not nons'r, a citizen of the United States, and to be resisted, cocoa or similar organic fibers.

a resident of Chicago, in the county of Cook These fibers serve as reinforcements and 5 and Stateof Illinois, have invented a cerstrengthen thebody of the material without tain new and useful Improvement in an adding to the weight thereof. r 60 Insulating Substance, of which the follow- In practice a satisfactory result may be in is a specification. Y secured by combining approximately 4 ly invention relates to heat insulating pounds of a suitable retarder with each ten materials'and particularly to a novel imof gypsum. This is aicommercial product provement in the composition of matter deand is so furnished 'when desired by the 65 scribed in my prior Patent No. 1,230,085. concerns which market the material.

In that patent I disclosed a com osition In making up the compound herein deof matter the major constituent 0 which scribed I prefer to .employ approximately 20 was asbestos in comminuted form and sugparts by volume of the so-described gypsum, gested. the possibility of employing other 2 parts by volume of magnesium carbonate 70 refractory materials including calcium suland 2 parts by volume of aluminum sulphate. phate or gypsum. However, long exper'r- The carbonate employed, whether it be that I ments failed to demonstrate any practical specified or some of the other carbonates, is.

value in this suggestion inasmuch as an ininsoluble in water, but the aluminum sulsulating material of sufficient lightness could phate, in commerclal'form, is soluble. Its 75 not be produced by employing calcium sulreaction with water results in releasing a I .phate as disclosed in that patent. While free acid,-in this case sulphuric acidthe reactions were prompt andvigorous and which in turn reacts with the carbonate, re-

the material became exceeding] porous in leasing carbon dioxide. Where a reinforccharacter, it would not remain 1n that coning element is to be employed I may add dition but immediately ffell. In other long', fiber asbestos or cocoa fiber in the prowords, while the mass seemed to rise in a portion of a proximately 5% by weight of most satisfactory manner and gave promise the mass; 1 is compound in its dry state is 30 of the production of a solid body of exinert. However, when itis to be utilizedatreme lightness, it invariably fell and in quantity of water is added theretosuificient its final form was much too heavy to be of to make a thick past-whereupon the leavenpractical use. v in action begins andthe mass expands or r I have discovered a means of obviatingv rises, thefinal volume being many times 35' this tendency and am able to produce an inthat of the mixture as formed. While stasulating material of extreme ightness; that bility of form is secured within' a short ,s, one in which the cellular structure is time, the final hardening is notcomplete for most pronounced and which is stable in 24 hours. v form. The result is secured by addin it Whether the permanency of thecellular 40 small quantity of a so-called retarder to structure is wholly attributable to the slowthe gypsum and then employing the gypsum ing up of the process of setting or whether as the principal constituent to which is addthis is merely incidental to'thecolloidal ef-. ed chemicals similar to those proposed in feet which followsthe use of the articular my prior patent heretofore referred to. I retarder, I am not aware. I wis it-to be" 4 amable to produce a substanceas light as understood, therefor, that the word, re-

12 pounds per cubic foot having a specific tarder is used-.asja broad term and that I avit as low as 0.19. This, as'will readily intend to include within" the scope of the und erstood, is of enormous-advantage not term, as used in theclaims, 'such'other sub only because of the relatively high insulatstances as will have the effect of' preventing 50 ing capacity but because of the'economy in the .escape of the as, and the consequent the use of. gypsum as the major constitucollapse of the cel ular structure, prior to ent. I hydraulic setting of the mass; 1

, Preferably also I mix with the materials By the word psum as used in the a small quantity of fibrous material such as specification and e um I refer to calcium order to secure a sulphate which has been partially calcined an will lsilydraulically set.

Obviou y the exact proportions Specified are not essential and neither is itnecessary duce a cellular structure, and approximately 5% by weight of fiber asbestos.

3. A new composltion of matter containing as its major ingredient a finely divided material, an insoluble carbonate, a sub-- stance which acts as a retarder, and a solid which upon the additionof water will release an acid which will in turn act on the car- 'a substance which acts e major ingredient, a rebonate to release carbon dioxide, said finely divided material beingin'ert relative to the gasaforniing substances.

,4. A new composition of calcium sulphate, an insoluble carbonate, as a. retarder, and a solid which upon the addition of water will release an acid which will inturn act on the carbonate to release carbon dioxide,

' 5-. The herein described composition of matter,- consistin of calcium sulphate as the major ingr ient, aluminum sulphate, an insoluble carbonate, and a retarder.

6; A new composition of matter composed :of calcium sulphate as the major ingredient,

'an insoluble carbonate, a retarder,and aluminum sulphate in dry mixture, whlch substances upon the add1tiono water evolve carbon dioxide and form a cellular structure which sets in that condition;

Signed at Chicago, 111., this 26th day of December, 1923. i

' HA OLD S..ASHENHURST.

ofmatte'r composed 

